The invention relates to a dynamometric cell with an elastically deformable force transducer for receiving a weight force and a sensor arrangement for detecting the deformation of the force transducer and its conversion into an electric weighing signal, wherein the force transducer is connected to a mounting member at a first end and supports a force introduction member at its second end.
Dynamometric cells of this type are used in a variety of ways and are known in different forms.
DE 44 206 91 C1, for example, describes a dynamometric cell with a force transducer in the form of a so-called parallelogram guide which is machined in one piece from a non-magnetic, electrically conductive material. The sensor arrangement comprises, in this case, an inductive sensor element which is arranged adjacent to the force introduction member of the force transducer opposite a signal-generating element on the side of the mounting member such that during stressing of the force introduction member with the force F an alteration in the distance between the sensor element and the signal-generating element, which is dependent on this force, results on account of the elastic deformation of the force transducer.
Such force transducers are often built into weighing devices and operate in this case with great reliability and high resolution.
Another type of force transducer is known, for example, from DE 35 15 126, with which the dynamometric cell comprises a flexurally elastic tubular bolt with a rigid measuring bar securely clamped in the cavity of the bolt on one side and a sensor inserted at the other end of the bolt. The free end of the measuring bar is located axially opposite the inductively operating sensor. The force is introduced between the end of the bolt and the clamping point of the rigid measuring bar. During flection of the bolt, the position of the free end of the measuring bar is altered in relation to the sensor and this alteration in location is detected by the sensors and converted into an electric signal. Such electromechanical dynamometers are well suited for the detection of large forces, wherein less value must be placed on precision. The dynamometric cell according to DE 38 43 869 C2 also operates by following a similar principle. This dynamometric cell is also suitable for detecting large forces with less precision.
All the aforementioned dynamometric cells have in common the fact that the force transducer is robust but of a relatively large construction and cannot, therefore, be used for a number of applications where a determination of a weight force would, as such, be desirable.
The object of the present invention is to further develop a dynamometric cell of the type described at the outset such that it can also be incorporated into narrow spaces and allows a more exact determination of weight force.